From a5f107da06bfded6b76d1404edfd5cf578f69c3f Mon Sep 17 00:00:00 2001 From: "Tim St. Clair" Date: Tue, 13 Sep 2016 13:50:53 -0700 Subject: [PATCH] Moved google.golang.org/cloud/compute/metadata to cloud.google.com/go/compute/metadata --- Godeps/Godeps.json | 22 +- utils/cloudinfo/gce.go | 2 +- .../cloud => cloud.google.com/go}/LICENSE | 0 .../go/compute/metadata/metadata.go | 438 ++++++++++++++++++ .../go}/internal/cloud.go | 18 +- .../x/net/context/ctxhttp/cancelreq.go | 18 + .../x/net/context/ctxhttp/cancelreq_go14.go | 23 + .../x/net/context/ctxhttp/ctxhttp.go | 79 ++++ .../cloud/compute/metadata/metadata.go | 221 --------- 9 files changed, 583 insertions(+), 238 deletions(-) rename vendor/{google.golang.org/cloud => cloud.google.com/go}/LICENSE (100%) create mode 100644 vendor/cloud.google.com/go/compute/metadata/metadata.go rename vendor/{google.golang.org/cloud => cloud.google.com/go}/internal/cloud.go (76%) create mode 100644 vendor/golang.org/x/net/context/ctxhttp/cancelreq.go create mode 100644 vendor/golang.org/x/net/context/ctxhttp/cancelreq_go14.go create mode 100644 vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go delete mode 100644 vendor/google.golang.org/cloud/compute/metadata/metadata.go diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json index a84fa943d7..19f34fabf2 100644 --- a/Godeps/Godeps.json +++ b/Godeps/Godeps.json @@ -11,6 +11,16 @@ "Comment": "null-5", "Rev": "'75cd24fc2f2c2a2088577d12123ddee5f54e0675'" }, + { + "ImportPath": "cloud.google.com/go/compute/metadata", + "Comment": "v0.1.0-115-g3b1ae45", + "Rev": "3b1ae45394a234c385be014e9a488f2bb6eef821" + }, + { + "ImportPath": "cloud.google.com/go/internal", + "Comment": "v0.1.0-115-g3b1ae45", + "Rev": "3b1ae45394a234c385be014e9a488f2bb6eef821" + }, { "ImportPath": "github.com/Microsoft/go-winio", "Comment": "v0.3.2", @@ -471,6 +481,10 @@ "ImportPath": "golang.org/x/net/context", "Rev": "5627bad10b821d907ac4dc81fb3535ec7dd81c2b" }, + { + "ImportPath": "golang.org/x/net/context/ctxhttp", + "Rev": "5627bad10b821d907ac4dc81fb3535ec7dd81c2b" + }, { "ImportPath": "golang.org/x/net/http2", "Rev": "5627bad10b821d907ac4dc81fb3535ec7dd81c2b" @@ -519,14 +533,6 @@ "ImportPath": "google.golang.org/api/googleapi/internal/uritemplates", "Rev": "0c2979aeaa5b573e60d3ddffe5ce8dca8df309bd" }, - { - "ImportPath": "google.golang.org/cloud/compute/metadata", - "Rev": "542bfb014d8e28df6e27be847dfdc40c510dab1a" - }, - { - "ImportPath": "google.golang.org/cloud/internal", - "Rev": "542bfb014d8e28df6e27be847dfdc40c510dab1a" - }, { "ImportPath": "google.golang.org/grpc", "Rev": "3c4302b7131d2b14bb9c8aff7aa909bc20540145" diff --git a/utils/cloudinfo/gce.go b/utils/cloudinfo/gce.go index 4c2e330dfe..b525451c05 100644 --- a/utils/cloudinfo/gce.go +++ b/utils/cloudinfo/gce.go @@ -20,8 +20,8 @@ import ( info "github.com/google/cadvisor/info/v1" + "cloud.google.com/go/compute/metadata" "github.com/golang/glog" - "google.golang.org/cloud/compute/metadata" ) const ( diff --git a/vendor/google.golang.org/cloud/LICENSE b/vendor/cloud.google.com/go/LICENSE similarity index 100% rename from vendor/google.golang.org/cloud/LICENSE rename to vendor/cloud.google.com/go/LICENSE diff --git a/vendor/cloud.google.com/go/compute/metadata/metadata.go b/vendor/cloud.google.com/go/compute/metadata/metadata.go new file mode 100644 index 0000000000..5c6f3bf382 --- /dev/null +++ b/vendor/cloud.google.com/go/compute/metadata/metadata.go @@ -0,0 +1,438 @@ +// Copyright 2014 Google Inc. All Rights Reserved. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Package metadata provides access to Google Compute Engine (GCE) +// metadata and API service accounts. +// +// This package is a wrapper around the GCE metadata service, +// as documented at https://developers.google.com/compute/docs/metadata. +package metadata + +import ( + "encoding/json" + "fmt" + "io/ioutil" + "net" + "net/http" + "net/url" + "os" + "runtime" + "strings" + "sync" + "time" + + "golang.org/x/net/context" + "golang.org/x/net/context/ctxhttp" + + "cloud.google.com/go/internal" +) + +const ( + // metadataIP is the documented metadata server IP address. + metadataIP = "169.254.169.254" + + // metadataHostEnv is the environment variable specifying the + // GCE metadata hostname. If empty, the default value of + // metadataIP ("169.254.169.254") is used instead. + // This is variable name is not defined by any spec, as far as + // I know; it was made up for the Go package. + metadataHostEnv = "GCE_METADATA_HOST" +) + +type cachedValue struct { + k string + trim bool + mu sync.Mutex + v string +} + +var ( + projID = &cachedValue{k: "project/project-id", trim: true} + projNum = &cachedValue{k: "project/numeric-project-id", trim: true} + instID = &cachedValue{k: "instance/id", trim: true} +) + +var ( + metaClient = &http.Client{ + Transport: &internal.Transport{ + Base: &http.Transport{ + Dial: (&net.Dialer{ + Timeout: 2 * time.Second, + KeepAlive: 30 * time.Second, + }).Dial, + ResponseHeaderTimeout: 2 * time.Second, + }, + }, + } + subscribeClient = &http.Client{ + Transport: &internal.Transport{ + Base: &http.Transport{ + Dial: (&net.Dialer{ + Timeout: 2 * time.Second, + KeepAlive: 30 * time.Second, + }).Dial, + }, + }, + } +) + +// NotDefinedError is returned when requested metadata is not defined. +// +// The underlying string is the suffix after "/computeMetadata/v1/". +// +// This error is not returned if the value is defined to be the empty +// string. +type NotDefinedError string + +func (suffix NotDefinedError) Error() string { + return fmt.Sprintf("metadata: GCE metadata %q not defined", string(suffix)) +} + +// Get returns a value from the metadata service. +// The suffix is appended to "http://${GCE_METADATA_HOST}/computeMetadata/v1/". +// +// If the GCE_METADATA_HOST environment variable is not defined, a default of +// 169.254.169.254 will be used instead. +// +// If the requested metadata is not defined, the returned error will +// be of type NotDefinedError. +func Get(suffix string) (string, error) { + val, _, err := getETag(metaClient, suffix) + return val, err +} + +// getETag returns a value from the metadata service as well as the associated +// ETag using the provided client. This func is otherwise equivalent to Get. +func getETag(client *http.Client, suffix string) (value, etag string, err error) { + // Using a fixed IP makes it very difficult to spoof the metadata service in + // a container, which is an important use-case for local testing of cloud + // deployments. To enable spoofing of the metadata service, the environment + // variable GCE_METADATA_HOST is first inspected to decide where metadata + // requests shall go. + host := os.Getenv(metadataHostEnv) + if host == "" { + // Using 169.254.169.254 instead of "metadata" here because Go + // binaries built with the "netgo" tag and without cgo won't + // know the search suffix for "metadata" is + // ".google.internal", and this IP address is documented as + // being stable anyway. + host = metadataIP + } + url := "http://" + host + "/computeMetadata/v1/" + suffix + req, _ := http.NewRequest("GET", url, nil) + req.Header.Set("Metadata-Flavor", "Google") + res, err := client.Do(req) + if err != nil { + return "", "", err + } + defer res.Body.Close() + if res.StatusCode == http.StatusNotFound { + return "", "", NotDefinedError(suffix) + } + if res.StatusCode != 200 { + return "", "", fmt.Errorf("status code %d trying to fetch %s", res.StatusCode, url) + } + all, err := ioutil.ReadAll(res.Body) + if err != nil { + return "", "", err + } + return string(all), res.Header.Get("Etag"), nil +} + +func getTrimmed(suffix string) (s string, err error) { + s, err = Get(suffix) + s = strings.TrimSpace(s) + return +} + +func (c *cachedValue) get() (v string, err error) { + defer c.mu.Unlock() + c.mu.Lock() + if c.v != "" { + return c.v, nil + } + if c.trim { + v, err = getTrimmed(c.k) + } else { + v, err = Get(c.k) + } + if err == nil { + c.v = v + } + return +} + +var ( + onGCEOnce sync.Once + onGCE bool +) + +// OnGCE reports whether this process is running on Google Compute Engine. +func OnGCE() bool { + onGCEOnce.Do(initOnGCE) + return onGCE +} + +func initOnGCE() { + onGCE = testOnGCE() +} + +func testOnGCE() bool { + // The user explicitly said they're on GCE, so trust them. + if os.Getenv(metadataHostEnv) != "" { + return true + } + + ctx, cancel := context.WithCancel(context.Background()) + defer cancel() + + resc := make(chan bool, 2) + + // Try two strategies in parallel. + // See https://github.com/GoogleCloudPlatform/google-cloud-go/issues/194 + go func() { + res, err := ctxhttp.Get(ctx, metaClient, "http://"+metadataIP) + if err != nil { + resc <- false + return + } + defer res.Body.Close() + resc <- res.Header.Get("Metadata-Flavor") == "Google" + }() + + go func() { + addrs, err := net.LookupHost("metadata.google.internal") + if err != nil || len(addrs) == 0 { + resc <- false + return + } + resc <- strsContains(addrs, metadataIP) + }() + + tryHarder := systemInfoSuggestsGCE() + if tryHarder { + res := <-resc + if res { + // The first strategy succeeded, so let's use it. + return true + } + // Wait for either the DNS or metadata server probe to + // contradict the other one and say we are running on + // GCE. Give it a lot of time to do so, since the system + // info already suggests we're running on a GCE BIOS. + timer := time.NewTimer(5 * time.Second) + defer timer.Stop() + select { + case res = <-resc: + return res + case <-timer.C: + // Too slow. Who knows what this system is. + return false + } + } + + // There's no hint from the system info that we're running on + // GCE, so use the first probe's result as truth, whether it's + // true or false. The goal here is to optimize for speed for + // users who are NOT running on GCE. We can't assume that + // either a DNS lookup or an HTTP request to a blackholed IP + // address is fast. Worst case this should return when the + // metaClient's Transport.ResponseHeaderTimeout or + // Transport.Dial.Timeout fires (in two seconds). + return <-resc +} + +// systemInfoSuggestsGCE reports whether the local system (without +// doing network requests) suggests that we're running on GCE. If this +// returns true, testOnGCE tries a bit harder to reach its metadata +// server. +func systemInfoSuggestsGCE() bool { + if runtime.GOOS != "linux" { + // We don't have any non-Linux clues available, at least yet. + return false + } + slurp, _ := ioutil.ReadFile("/sys/class/dmi/id/product_name") + name := strings.TrimSpace(string(slurp)) + return name == "Google" || name == "Google Compute Engine" +} + +// Subscribe subscribes to a value from the metadata service. +// The suffix is appended to "http://${GCE_METADATA_HOST}/computeMetadata/v1/". +// The suffix may contain query parameters. +// +// Subscribe calls fn with the latest metadata value indicated by the provided +// suffix. If the metadata value is deleted, fn is called with the empty string +// and ok false. Subscribe blocks until fn returns a non-nil error or the value +// is deleted. Subscribe returns the error value returned from the last call to +// fn, which may be nil when ok == false. +func Subscribe(suffix string, fn func(v string, ok bool) error) error { + const failedSubscribeSleep = time.Second * 5 + + // First check to see if the metadata value exists at all. + val, lastETag, err := getETag(subscribeClient, suffix) + if err != nil { + return err + } + + if err := fn(val, true); err != nil { + return err + } + + ok := true + if strings.ContainsRune(suffix, '?') { + suffix += "&wait_for_change=true&last_etag=" + } else { + suffix += "?wait_for_change=true&last_etag=" + } + for { + val, etag, err := getETag(subscribeClient, suffix+url.QueryEscape(lastETag)) + if err != nil { + if _, deleted := err.(NotDefinedError); !deleted { + time.Sleep(failedSubscribeSleep) + continue // Retry on other errors. + } + ok = false + } + lastETag = etag + + if err := fn(val, ok); err != nil || !ok { + return err + } + } +} + +// ProjectID returns the current instance's project ID string. +func ProjectID() (string, error) { return projID.get() } + +// NumericProjectID returns the current instance's numeric project ID. +func NumericProjectID() (string, error) { return projNum.get() } + +// InternalIP returns the instance's primary internal IP address. +func InternalIP() (string, error) { + return getTrimmed("instance/network-interfaces/0/ip") +} + +// ExternalIP returns the instance's primary external (public) IP address. +func ExternalIP() (string, error) { + return getTrimmed("instance/network-interfaces/0/access-configs/0/external-ip") +} + +// Hostname returns the instance's hostname. This will be of the form +// ".c..internal". +func Hostname() (string, error) { + return getTrimmed("instance/hostname") +} + +// InstanceTags returns the list of user-defined instance tags, +// assigned when initially creating a GCE instance. +func InstanceTags() ([]string, error) { + var s []string + j, err := Get("instance/tags") + if err != nil { + return nil, err + } + if err := json.NewDecoder(strings.NewReader(j)).Decode(&s); err != nil { + return nil, err + } + return s, nil +} + +// InstanceID returns the current VM's numeric instance ID. +func InstanceID() (string, error) { + return instID.get() +} + +// InstanceName returns the current VM's instance ID string. +func InstanceName() (string, error) { + host, err := Hostname() + if err != nil { + return "", err + } + return strings.Split(host, ".")[0], nil +} + +// Zone returns the current VM's zone, such as "us-central1-b". +func Zone() (string, error) { + zone, err := getTrimmed("instance/zone") + // zone is of the form "projects//zones/". + if err != nil { + return "", err + } + return zone[strings.LastIndex(zone, "/")+1:], nil +} + +// InstanceAttributes returns the list of user-defined attributes, +// assigned when initially creating a GCE VM instance. The value of an +// attribute can be obtained with InstanceAttributeValue. +func InstanceAttributes() ([]string, error) { return lines("instance/attributes/") } + +// ProjectAttributes returns the list of user-defined attributes +// applying to the project as a whole, not just this VM. The value of +// an attribute can be obtained with ProjectAttributeValue. +func ProjectAttributes() ([]string, error) { return lines("project/attributes/") } + +func lines(suffix string) ([]string, error) { + j, err := Get(suffix) + if err != nil { + return nil, err + } + s := strings.Split(strings.TrimSpace(j), "\n") + for i := range s { + s[i] = strings.TrimSpace(s[i]) + } + return s, nil +} + +// InstanceAttributeValue returns the value of the provided VM +// instance attribute. +// +// If the requested attribute is not defined, the returned error will +// be of type NotDefinedError. +// +// InstanceAttributeValue may return ("", nil) if the attribute was +// defined to be the empty string. +func InstanceAttributeValue(attr string) (string, error) { + return Get("instance/attributes/" + attr) +} + +// ProjectAttributeValue returns the value of the provided +// project attribute. +// +// If the requested attribute is not defined, the returned error will +// be of type NotDefinedError. +// +// ProjectAttributeValue may return ("", nil) if the attribute was +// defined to be the empty string. +func ProjectAttributeValue(attr string) (string, error) { + return Get("project/attributes/" + attr) +} + +// Scopes returns the service account scopes for the given account. +// The account may be empty or the string "default" to use the instance's +// main account. +func Scopes(serviceAccount string) ([]string, error) { + if serviceAccount == "" { + serviceAccount = "default" + } + return lines("instance/service-accounts/" + serviceAccount + "/scopes") +} + +func strsContains(ss []string, s string) bool { + for _, v := range ss { + if v == s { + return true + } + } + return false +} diff --git a/vendor/google.golang.org/cloud/internal/cloud.go b/vendor/cloud.google.com/go/internal/cloud.go similarity index 76% rename from vendor/google.golang.org/cloud/internal/cloud.go rename to vendor/cloud.google.com/go/internal/cloud.go index db37727282..8e0c8f8e52 100644 --- a/vendor/google.golang.org/cloud/internal/cloud.go +++ b/vendor/cloud.google.com/go/internal/cloud.go @@ -24,24 +24,26 @@ import ( const userAgent = "gcloud-golang/0.1" -// UATransport is an http.RoundTripper that appends -// Google Cloud client's user-agent to the original -// request's user-agent header. -type UATransport struct { - // Base represents the actual http.RoundTripper - // the requests will be delegated to. +// Transport is an http.RoundTripper that appends Google Cloud client's +// user-agent to the original request's user-agent header. +type Transport struct { + // TODO(bradfitz): delete internal.Transport. It's too wrappy for what it does. + // Do User-Agent some other way. + + // Base is the actual http.RoundTripper + // requests will use. It must not be nil. Base http.RoundTripper } // RoundTrip appends a user-agent to the existing user-agent // header and delegates the request to the base http.RoundTripper. -func (t *UATransport) RoundTrip(req *http.Request) (*http.Response, error) { +func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) { req = cloneRequest(req) ua := req.Header.Get("User-Agent") if ua == "" { ua = userAgent } else { - ua = fmt.Sprintf("%s;%s", ua, userAgent) + ua = fmt.Sprintf("%s %s", ua, userAgent) } req.Header.Set("User-Agent", ua) return t.Base.RoundTrip(req) diff --git a/vendor/golang.org/x/net/context/ctxhttp/cancelreq.go b/vendor/golang.org/x/net/context/ctxhttp/cancelreq.go new file mode 100644 index 0000000000..48610e3627 --- /dev/null +++ b/vendor/golang.org/x/net/context/ctxhttp/cancelreq.go @@ -0,0 +1,18 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build go1.5 + +package ctxhttp + +import "net/http" + +func canceler(client *http.Client, req *http.Request) func() { + ch := make(chan struct{}) + req.Cancel = ch + + return func() { + close(ch) + } +} diff --git a/vendor/golang.org/x/net/context/ctxhttp/cancelreq_go14.go b/vendor/golang.org/x/net/context/ctxhttp/cancelreq_go14.go new file mode 100644 index 0000000000..56bcbadb85 --- /dev/null +++ b/vendor/golang.org/x/net/context/ctxhttp/cancelreq_go14.go @@ -0,0 +1,23 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !go1.5 + +package ctxhttp + +import "net/http" + +type requestCanceler interface { + CancelRequest(*http.Request) +} + +func canceler(client *http.Client, req *http.Request) func() { + rc, ok := client.Transport.(requestCanceler) + if !ok { + return func() {} + } + return func() { + rc.CancelRequest(req) + } +} diff --git a/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go b/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go new file mode 100644 index 0000000000..9f34888132 --- /dev/null +++ b/vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go @@ -0,0 +1,79 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package ctxhttp provides helper functions for performing context-aware HTTP requests. +package ctxhttp + +import ( + "io" + "net/http" + "net/url" + "strings" + + "golang.org/x/net/context" +) + +// Do sends an HTTP request with the provided http.Client and returns an HTTP response. +// If the client is nil, http.DefaultClient is used. +// If the context is canceled or times out, ctx.Err() will be returned. +func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) { + if client == nil { + client = http.DefaultClient + } + + // Request cancelation changed in Go 1.5, see cancelreq.go and cancelreq_go14.go. + cancel := canceler(client, req) + + type responseAndError struct { + resp *http.Response + err error + } + result := make(chan responseAndError, 1) + + go func() { + resp, err := client.Do(req) + result <- responseAndError{resp, err} + }() + + select { + case <-ctx.Done(): + cancel() + return nil, ctx.Err() + case r := <-result: + return r.resp, r.err + } +} + +// Get issues a GET request via the Do function. +func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("GET", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Head issues a HEAD request via the Do function. +func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) { + req, err := http.NewRequest("HEAD", url, nil) + if err != nil { + return nil, err + } + return Do(ctx, client, req) +} + +// Post issues a POST request via the Do function. +func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) { + req, err := http.NewRequest("POST", url, body) + if err != nil { + return nil, err + } + req.Header.Set("Content-Type", bodyType) + return Do(ctx, client, req) +} + +// PostForm issues a POST request via the Do function. +func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) { + return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode())) +} diff --git a/vendor/google.golang.org/cloud/compute/metadata/metadata.go b/vendor/google.golang.org/cloud/compute/metadata/metadata.go deleted file mode 100644 index 6e6fde8565..0000000000 --- a/vendor/google.golang.org/cloud/compute/metadata/metadata.go +++ /dev/null @@ -1,221 +0,0 @@ -// Copyright 2014 Google Inc. All Rights Reserved. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -// Package metadata provides access to Google Compute Engine (GCE) -// metadata and API service accounts. -// -// This package is a wrapper around the GCE metadata service, -// as documented at https://developers.google.com/compute/docs/metadata. -package metadata - -import ( - "encoding/json" - "fmt" - "io/ioutil" - "net" - "net/http" - "strings" - "sync" - "time" - - "google.golang.org/cloud/internal" -) - -type cachedValue struct { - k string - trim bool - mu sync.Mutex - v string -} - -var ( - projID = &cachedValue{k: "project/project-id", trim: true} - projNum = &cachedValue{k: "project/numeric-project-id", trim: true} - instID = &cachedValue{k: "instance/id", trim: true} -) - -var metaClient = &http.Client{ - Transport: &internal.UATransport{ - Base: &http.Transport{ - Dial: (&net.Dialer{ - Timeout: 750 * time.Millisecond, - KeepAlive: 30 * time.Second, - }).Dial, - ResponseHeaderTimeout: 750 * time.Millisecond, - }, - }, -} - -// Get returns a value from the metadata service. -// The suffix is appended to "http://metadata/computeMetadata/v1/". -func Get(suffix string) (string, error) { - // Using 169.254.169.254 instead of "metadata" here because Go - // binaries built with the "netgo" tag and without cgo won't - // know the search suffix for "metadata" is - // ".google.internal", and this IP address is documented as - // being stable anyway. - url := "http://169.254.169.254/computeMetadata/v1/" + suffix - req, _ := http.NewRequest("GET", url, nil) - req.Header.Set("Metadata-Flavor", "Google") - res, err := metaClient.Do(req) - if err != nil { - return "", err - } - defer res.Body.Close() - if res.StatusCode != 200 { - return "", fmt.Errorf("status code %d trying to fetch %s", res.StatusCode, url) - } - all, err := ioutil.ReadAll(res.Body) - if err != nil { - return "", err - } - return string(all), nil -} - -func getTrimmed(suffix string) (s string, err error) { - s, err = Get(suffix) - s = strings.TrimSpace(s) - return -} - -func (c *cachedValue) get() (v string, err error) { - defer c.mu.Unlock() - c.mu.Lock() - if c.v != "" { - return c.v, nil - } - if c.trim { - v, err = getTrimmed(c.k) - } else { - v, err = Get(c.k) - } - if err == nil { - c.v = v - } - return -} - -var onGCE struct { - sync.Mutex - set bool - v bool -} - -// OnGCE reports whether this process is running on Google Compute Engine. -func OnGCE() bool { - defer onGCE.Unlock() - onGCE.Lock() - if onGCE.set { - return onGCE.v - } - onGCE.set = true - - // We use the DNS name of the metadata service here instead of the IP address - // because we expect that to fail faster in the not-on-GCE case. - res, err := metaClient.Get("http://metadata.google.internal") - if err != nil { - return false - } - onGCE.v = res.Header.Get("Metadata-Flavor") == "Google" - return onGCE.v -} - -// ProjectID returns the current instance's project ID string. -func ProjectID() (string, error) { return projID.get() } - -// NumericProjectID returns the current instance's numeric project ID. -func NumericProjectID() (string, error) { return projNum.get() } - -// InternalIP returns the instance's primary internal IP address. -func InternalIP() (string, error) { - return getTrimmed("instance/network-interfaces/0/ip") -} - -// ExternalIP returns the instance's primary external (public) IP address. -func ExternalIP() (string, error) { - return getTrimmed("instance/network-interfaces/0/access-configs/0/external-ip") -} - -// Hostname returns the instance's hostname. This will probably be of -// the form "INSTANCENAME.c.PROJECT.internal" but that isn't -// guaranteed. -// -// TODO: what is this defined to be? Docs say "The host name of the -// instance." -func Hostname() (string, error) { - return getTrimmed("network-interfaces/0/ip") -} - -// InstanceTags returns the list of user-defined instance tags, -// assigned when initially creating a GCE instance. -func InstanceTags() ([]string, error) { - var s []string - j, err := Get("instance/tags") - if err != nil { - return nil, err - } - if err := json.NewDecoder(strings.NewReader(j)).Decode(&s); err != nil { - return nil, err - } - return s, nil -} - -// InstanceID returns the current VM's numeric instance ID. -func InstanceID() (string, error) { - return instID.get() -} - -// InstanceAttributes returns the list of user-defined attributes, -// assigned when initially creating a GCE VM instance. The value of an -// attribute can be obtained with InstanceAttributeValue. -func InstanceAttributes() ([]string, error) { return lines("instance/attributes/") } - -// ProjectAttributes returns the list of user-defined attributes -// applying to the project as a whole, not just this VM. The value of -// an attribute can be obtained with ProjectAttributeValue. -func ProjectAttributes() ([]string, error) { return lines("project/attributes/") } - -func lines(suffix string) ([]string, error) { - j, err := Get(suffix) - if err != nil { - return nil, err - } - s := strings.Split(strings.TrimSpace(j), "\n") - for i := range s { - s[i] = strings.TrimSpace(s[i]) - } - return s, nil -} - -// InstanceAttributeValue returns the value of the provided VM -// instance attribute. -func InstanceAttributeValue(attr string) (string, error) { - return Get("instance/attributes/" + attr) -} - -// ProjectAttributeValue returns the value of the provided -// project attribute. -func ProjectAttributeValue(attr string) (string, error) { - return Get("project/attributes/" + attr) -} - -// Scopes returns the service account scopes for the given account. -// The account may be empty or the string "default" to use the instance's -// main account. -func Scopes(serviceAccount string) ([]string, error) { - if serviceAccount == "" { - serviceAccount = "default" - } - return lines("instance/service-accounts/" + serviceAccount + "/scopes") -}